About 700 species/subspecies soil darkling beetles, belonging to 24 tribes of 3 subfamilies are known from China. They will be treated in 4 volumes of a monograph. The present volume described 1 species in tribe Leichenini, 1 species in tribe ldisiini, and 148 species of 20 genera in tribe Opatrini, including 4 new species and 4 new records from China. Total 107 portraits and 140 character figures are illustrated.

The introduction account in this volume includes the brief history of classified research, morphological characters, materials and methods, system of classification, biology and economical importance of the Opatriformes, phylogenetic relationship of the Opatriformes, fauna and geographical distribution of the Opatriformes,. Henning 86 program is used for cladistic analysis of 14 genera in the tribe Opatrini. The cladograin shows these genera came from two different origins: a monophyly is the genus Mesomorphus, and the other is composed of 13 genera. The results of fauna and geography analysis revealed 59.1% genera from Chinese Opatrini are distributed in Palaearctic region, among which 40.9% are central asia origin. Except for genus Gonocephalum, with a wide distribution, the major staple species and subspecies in China are from central Asia, others are limited in a narrow region. Possible origins for these species are two ways; Mongolia-Xinjiang arid region and south-China sub-tropic region.

In the classification part, 1 species of 1 genus in tribe Leichenini, 1 species of 1 genus in tribe Idisiini, 148 species of 20 genera in tribe Opatrini are described and illustrated. Synonyms and distributions for each species are provided. Keys to genera and species are developed. Morphological characters and photographs are also given. Four species are described as new to science, two new synonyms are proposed.

Part I: General Account
1.Brief history of classified research
2.Morphological characters
3.Materials and methods
4.System of classification
5.Biology and economical importance of the Opatriformes
6.Phylogenetic relationship of the Opatriformes
7.Fauna and geographical distribution of the Opatriformes
Part II. Classificatory Account
1.Leichenini Medvedev, 1973
2.Idisiini Medvedev, 1973
3.Opatrini Brulle, 1832
Part III: References
Part IV: Chinese Abstract
Part V: English Abstract
Part VI: Index of Chinese name
Part VII: Index of scientific name
Part VIII: Plate